Centrifugal casting



Sept. 1-, 1925;

R. sTREsAu GEN TRIFUGAL CASTING Filed July 19 1923 INVENTOR.

fif c/mrd \Yfresau, WATTORNEYS.

'thesamewithasu Patented Se t 1-, j UNITED- STATES.

mcmnn srnnsau, or wauwarosa, wrscousm, ASSIGNOB To a. o. snrrn conrona-1,551,590 PATENT- oFFicn.

, I T1011, 01 IILWAUKEE, WISCONSIN, A CORPORATION 01 NEW YORK.

cam-nirvana cas'rmo.

. Application fled my 1a, 1923. Serial no. 055,495.

To all whom it may concern:

Be 't known that I, "RICHARD STRESAU, a citizen of the United States,and a' resident of the city of Wauwatosa,in the county of .Milwaukee andState of Wisconsin, have invented certain new and useful Improvements inCentrifugal Castings; and I do declare the followin to be a clear,exact,-and

complete 'descri tion thereof, such as'will' enable others skilled inthe art to which the invention pertains tense and practice the same.

My invention relates in general to the 1'5- casting of tubular articles,and in particular to pi couplings, by the centrifugal process,

m w 'ch a measured quantity 'of.molten'-' metal is poured into acylindrical mold during the rotation of the latter. By virtue'of therotation of the mold up'on itslongitudir nal axis at a'high :rate ofspeed, the metal is caused by centrifugal force to flow evenly againstthe moldin surface so as to cover stantially'uniform den:

sity and reduce a 'hollow castin the w of w 'ch are of uniform thic essth hout.

'- themodw Al ough this manner ofcasting is a simle matterand is easilyaccomplished, it is ound that the casting m chilling sometimes sticks tothe steel mold, requiring an exnditure of time in removing the casting mthe mold as well as incurring an mterruption of the casting operationsdue to such exigency. s

My present inventioncomprises theprovision of a means for remedyin thead- ,yerse conditions referred to, an

which I am enabled to practice centrifugal through casting in amanner inwhich all liability of the casting to stick to the mold is eliminated,and to permit discharge of the casting fromithout loss of time orinterrup 'tion of the casting. operation as a continuous be a mold priorto each casting one.

This result I achieve'by in the 7 cast linformed as a thin sheet-o metalhavi su tially the character and pro es 0 the metal being cast. Thelining eet conforms closely to and cmnpletely coversthe curved moldingsurface, andjmay or may not lining will be i 111ml, mold-during-the ofthe latter, and

1to to the casting operation.

provided wit I rapi of which the-molten as the latter is introduced intothe be incorporated as an integral part of the casting; But the lowtemperature existing between the contiguous surfaces of the mold and thelining will act as a chill to overcome any tendency whichthe castingmight have to stick to the mold. Y

Although the lining is fused into the casting, the finished exterior ofthe rolled sheet from which the lining is formed is preservedpractically in its primary state, so

that a much better finish is imparted to' the outer surface of thecasting, in that the same in carrying out my invention, and willconclude with claims definingthe novelty of the latter.

In the drawings: I) M Figure 1 is a lo itudinal sectional view throughthe vertica axis of a water-cooled centrifugal casting machine, built in'accordance with my invention, and preparag. 2 is a vertical sectionalview of the machine shown in Fig. 1, on a l 1ne transverse toithe' axisof the mold, and taken at any point between the ends of the mold.

Referring to .the drawing, the numeral indicates the cylindrical hardmetal mold of a centrifugal casting machine designed for use in castmtubular articles. The mold is iheads 11 and 12 having journals 13 and14', which are mounted for rotation in bearings 15 and 16. The journal15is rovided with driven means, as a belt pu e 17, through which amovement of rotation is imparted to the mold 10. The journal 16 ishollow and open from end to end, so that the molten metal may beintroduced into the mold through the funnel trough 18, the. dischargingend throu 'h the hollow journal and-m'to the mo d.' The funnel or trou'h may be supported in relatively 1 fix positionuponthe bearing 16 bymeans of the bracket 19, or it ma be independently described, thearrangement is quite usual. It

will increase the capacity for production by the apparatus to providethe mold with a concentrically arranged covering 20, spaced from themold to constitute a water jacket,

so that Water may circulate through the space 21 and effect reduction ofthe temperatures within the molds.

But in the absence of any provision of cooling means, and even whenused, it sometimes occurs that the casting will stick tothe mold, andcan be dislodged therefrom only by an expenditure of time and labor,With a consequent unnecessary interruption and delay in casting as.a-continuous operation.

My invention obviates these difiiculties and delays. In achieving itspurposes, I line the'mold with a thin sheetof metal having theproperties of the metal which is being cast. The lining occupiesthe'length of the mold and is in the form of a tube 22, either seamed ornot at the meeting edges 23 of the sheet out of which it is formed, andbears a snug contact with the whole of the inside surface of the mold.

When ready for casting the mold is lined as described and rapid rotationimparted thereto. Molten metal in a measured uantity is introduced intothe mold, and qulckly distributes itself evenly over the interiorsurface of the lining, due to centrifugal force, with the result that acasting uniform in the density and thickness of its tubular wall isproduced. The contact of the molten' metal with the lining fuses thelatter into such a state that it becomes anintegral part of the casting,and loses its character as a shell in the amalgamation which takesplace.

Although the fusion of the linin is complete, the casting will not stickto t e mold, due to the lower temperature created by the contact of thesurfaces of the hard metal mold and the lining, whereby a chillingeffect is produced in the area of such contact.

The proportions of the casting are indicated by the broken lines in thedrawing.

The practice of my invention has enabled me to produce a better finishupon the outer surface of the casting, inasmuch as the original surfaceof the rolled sheet from which the lining is shaped is preserved in muchof its entirety, and the surface cracks usually formed upon centrifugalcastings are obviated.

specifically application Serial N 0. 18,229, filed by me on March 25,1925.

Having'thus described my invention, what I claim and desire to secure byLetters Patent of the United States, is:

1. The process of casting a pipe couplin which comprises the steps oflining a mold with a thin sheet of metal, introducing into the moldduring the periods of rotation of the latter a quantity of molten metal,and fusing and amalgamating the lining into a finished integral exteriorsurface of the tubular casting free from cracks.

2. The process of casting a pipe coupling which comprises the steps oflining a rotatable mold with a thin sheet of metal, intro ducing intothe rotating mold a quantity of molten metal in the form of a layerofuniform thickness, and fusing and amalgamating the lining as anintegral part of the casting by the centrifugal contact of the moltenmetal therewith, to constitute a finished exterior surface for thecasting free from cracks. f H 1.

3. In centri uga castin i e cou in 's the method of prevla nting 51Easting frd m stickin a metal introduction of molten metal to form achill between the surface of the moldand the molten metal, and fusingthe lining in the contact of the molten metal therewith so as toconstitute an integral exterior surface for the casting free fromcracks.

In testimony whereof, I have signed my name at-Milwaukee, this 17th dayof July,

- R. STRESAU.

mold with sheet metal prior to the into the mold,

to the mold, which consists in lining

